Sound insulation is the set of structural measures that blocks or reduces the transmission of sound between two spaces, so that less sound passes from one room to another.
How sound insulation works
Sound travels as vibrations through air and through structures. Sound insulation works by blocking or damping those vibrations. Two types are distinguished:
- Airborne sound: sound travelling through the air, such as voices and music
- Impact sound: sound transmitted through the structure, such as footsteps or a slamming door
The insulation value is expressed by the Rw value (in decibels): the higher the Rw value, the better the insulation.
| Principle | Effect |
|---|---|
| Mass | Heavy walls block sound better |
| Decoupling | Separated layers break the vibration |
| Absorption | Soft material in a cavity damps the sound |
Application
Sound insulation is essential in housing, offices and schools. Examples include:
- Heavy or double walls and cavity walls
- Floating screed floors against impact sound
- Insulation with mineral wool in walls and floors
- Sealing gaps and acoustically glazed windows
Note the difference from sound absorption: insulation blocks sound between spaces, while absorption reduces reverberation within a single room.
Related terms
- Insulation
- Airborne sound
- Impact sound
- Cavity wall
- Mineral wool
- Decibel
- Sound absorption
Looking for more DIY plans? Check out fredsdiyplans.com.